Restrictive Lung Diseases

1. Adult respiratory distress syndrome 2. Sarcoidosis 3. Asbestosis 4. Neonatal respiratory distress syndrome 5. Idiopathic Pulmonary fibrosis Restrictive Lung Diseases

Acute respiratory distress syndrome 1.Def: Diffuse damage primarily to type 1 pneumocytes + capillary: followed by injury of type 2 cells and endothelium. 2.Cause: gm - ve Sepsis, trauma, lung infection etc. 3.Pathogenesis: 1.Diffuse alveolar damage: DAD 2.In E coli infection this DAD is mediated by free radicals from Neutrophils.

Respiratory membrane Alveolar sac

Hyaline membrane

ARDS Morphology: –Gross: lung is diffusely firm, airless, and rubbery. –Micro: Hyaline membrane Clinical: –acute dyspnea, cyanosis, hypoxemia. –X ray: white out : bilateral lung opacity –Unresponsive to 100% oxygen treatment. –Mortality is between 30-40%.

Intra alveolar hyaline membrane: fibrin and cell debris → reduced oxygen diffusion. Whiteout End

Neonatal respiratory distress syndrome Reduced surfactant due to defective pneumocytes 2. Clinical similar to ARDS

Sarcoidosis

Sarcoidosis Definition: disease with non caseating granulomas, can involve any organ. Most common presentation. –Bilateral hilar lymphadenopathy and /or lung involvement. Hyper-calcemia is present ( due to high 1,25- dihydroxyvitamin D by sarcoid macrophage).

Morphology: Micro Microscopy : –Non caseating epithelioid cell granulomas in all effected organs with giant cells. –Hilar node: These lympnnode may undergo calcification: egg shell calcification.

Asteroid bodies Schuamann body Giant cells contain these structures Concentric calcification

Clinical Course of Sarcoidosis Asymptomatic, discovered incidentally (many cases). Dry cough/ night sweat/ fever. Eye involvement: Mikulicz syndrome: corneal opacity, blindness. Skin involvement: erythema nodosum (painful erythematous plaques or rash).

Sarcoidosis : diagnosis Final diagnosis is by lung LN biopsy or biopsy of the skin or eye lesion. Helpful: CD4/CD8 ratio >2.5 ( in bronchoalveolar lavage lymphocytes ) – PPD negative. End

Asbestosis Cause: Asbestos fibers Morphology of lung: Early: diffuse interstitial fibrosis in lower lobe and fibrous pleural plaque [parietal pleura]. Late stage: honeycomb lung. Complications: bronchogenic carcinoma, mesothelioma.

Asbestos fibers : morphology Asbestos body or Ferruginous body which is positive with Prussian blue. –Amphibole (thin and straight) and serpentine (curly. Flexible, common ). –Present in extracellular tissue in lung interstitium (initial ingested by macrophage that eventually dies off).

Asbestosis : morphology Ferruginous body which is positive with Prussian blue. They arise when macrophages attempt to phagocytose asbestos fibers.

Late change: “Honeycomb" lung. It is the end stage of all restrictive lung diseases

Pulmonary hypertension

Pulmonary hypertension → right ventricular hypertrophy. PrimarySecondary More common 1. Multiple pulmonary emboli 2. Increased blood flow ( left-to-right shunt). 3. COPD and restrictive lung disease : these cause hypoxia induced vasoconstriction.

Primary Pulmonary Hypertension Etiology: unknown Morphology: plexiform pulmonary angiopathy and medial hypertrophy.

Secondary Pulmonary Hypertension Morphology: –Medial hypertrophy –Or presence fibrotic organized emboli in vessels with narrow lumen.

Complications of Pulmonary Hypertension Right ventricular hypertrophy → Right heart failure or cor pulmonale

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